The control of adenovirus gene expression will be studied with particular emphasis on the viral nucleic acids. In order to characterize viral gene expression in detail, two complementing approaches will be developed. The detailed analysis of viral functions will utilize specific viral DNA fragments as probes for expression of defined regions of the genome. These DNA fragments will be prepared by cleavage of viral genomes with various restriction enconucleases. Second, this analysis will include different physiological conditions in which viral genes are expresed. Such conditions include productively and abortively infected cells, transformed cell lines and the expression of mutant viral genomes in non-permissive conditions.